In the game of golf, a variety of clubs including drivers, irons and putters are used. Putting in particular is a most demanding aspect of the game, and a wide variety of putter designs have been proposed to enhance putting performance.
For example, U.S. Pat. No. 5,160,142 discloses a putting training device with a housing for a ball and a plurality of angularly disposed pockets into which the ball can roll during the putting stroke. U.S. Pat. No. 4,135,720 discloses another such device. U.S. Pat. No. 4,194,739 discloses an adjustable putter. U.S. Pat. No. 5,219,169 discloses a golf club with a bubble indicator. U.S. Pat. No. 4,082,286 discloses another golf club with bubble indicator. U.S. Pat. No. 5,195,747 discloses a golf club with weights which are movable to maintain the center of inertia in the same location regardless of club swing plane. U.S. Pat. No. 5,613,916 discloses a golf club with mass elements which are movable to attenuate shock and vibration. U.S. Pat. No. 5,492,329 discloses a golf putter with an LED leveling device.
Notwithstanding the many attempts to design a putter that offers the prospect of significantly improved performance, golfers continue to seek ways to enhance their performance and improve their scores. Putting is said to be the most crucial aspect of the game. That is, while the shots from the tee to the green require skill and accuracy, they also require power. Improvements in driving accuracy are not likely to improve a golfer's scores in the absence of distance improvements. In putting, by contrast, the possibility of score improvements resides entirely in improvements in skill, accuracy and technique. Moreover, a large majority of the shots taken by golfers are putts. Accordingly, golfers have long sought ways to improve their putting as the only feasible means of improving their scores.
One of the key difficulties in putting is development of a consistent, uniform stroke. It is very important in this respect for the golfer to keep the head down and the eyes on the ball. A common failing is the propensity to focus on the hole or the anticipated path of the ball as it travels toward the hole. Thus, a golfer may often raise the eyes toward the hole before the putting stroke is complete, and in the process will move the shoulders and throw the stroke off line.
An indicator on the club which requires the golfer's attention throughout the putting stroke will encourage the golfer to keep the head down and the focus of attention where it should be. An indicator can also serve the purpose of indicating to the golfer whether the putting stroke is on or off line.